Advances in plasma processing have provided for growth in the semiconductor industry. To be competitive in the semiconductor industry, a manufacturing company needs to be able to minimize waste during substrate processing. Accordingly, maintaining tight control of the process parameters during substrate processing is essential for reducing waste and producing high quality semiconductor devices.
In a plasma processing system, plasma is formed above a substrate to perform substrate processing. In order to control plasma formation and to protect the process chamber walls, confinement rings may be employed. Typically, the confinement rings are configured to surround the periphery of the chamber volume in which plasma is to form.
The confinement rings may include multiple rings stacked on top of one another. The gap between the confinement rings may be adjusted to control the volume of pressure within the confined area. In other words during substrate processing, if the chamber pressure is outside of the designated range (such as that determined by the current recipe), the confinement rings may be adjusted. In an example, to increase the pressure within the processing chamber, the gap between the confinement rings may be reduced.
Accordingly, an arrangement for controlling the movement of the confinement rings is desirable in order to maintain tight control of the pressure parameter during substrate processing.